Principles of Ecology See New Kent PPT for SOL questions and string food web activity

Ecology – what is it? Scientific discipline that studies the relationships of organisms with each other and their environments. Ecologists perform experiments to understand why these relationships might occur. Biosphere – portion of earth that supports life!

Biotic v. Abiotic Factors Biotic factors – living things! Other organisms Abiotic factors – non-living things… Temperature Air or water currents Sunlight Soil type Nutrients Still important for survival!

Levels of Organization Organism – bear Population (of one species) – group of bears (biological) Community (interacting, living populations) – bears and other organisms that live nearby Ecosystem (living and non-living) – woodland ecosystem Biome (many ecosystems – similar climate) – temperate forest Biosphere (all biomes on earth) – earth

Ecosystems and Their Energy

Ecosystem Interactions Competition (resources) v. predation (plants too!) Due to competition, chances for survival are increased when any one species uses the available resources in different ways. Niche – role or position that an organism has in its environment Habitat – area where an organism lives

Symbiotic Relationships All examples of symbiosis – two (or more) species living closely together Mutualism – two or more organisms that benefit from each other. Commensalism – one organisms benefits, the other neither benefits nor is harmed (Nemo!). Parasitism – one organism benefits, the other is harmed. Mutualism – coral. Coral protects, algae provides nutrients!

Flow of Energy in an Ecosystem Autotroph – collects energy from the sun to produce food Heterotroph – gets its energy by consuming other organisms Herbivore Carnivore Omnivores Scavengers – hyena Detritivores or decomposers – eat and break down parts of dead organisms and retain their nutrients so they can be reused What would happen if detitivores didn’t exist?

Wood louse decomposing dead plants!

Models of Energy Flow Food chains and food webs Have different trophic levels Where does energy begin? Producers, Consumers (Primary, Secondary, Tertiary) Each step in the food chain/web Arrows represent the flow of energy Why would we use webs instead of chains?

Energy and Biomass Pyramids

How do the two relate?

Energy Pyramids – Instructions Pick a food chain and go to page 72-73 in your textbook (4 extras) Trophic Level – using the appropriate term Example – drawing (include word if not clear) Side three Numbers – how many organisms? (given for you) Energy (Joules – unit of energy) and Biomass (total mass for one trophic level) – you are given base level, how will you find the rest? Color, Cut, Fold, Affix, and you’re done! RAM JAM!!!

Example food chain MAY NOT USE this one 10,000 J (energy) 1,000 J 100 J 10 J 6000 (numbers) 250 10,000n kg (biomass) 40 3 1,000n kg 100n kg 10n kg fold here cut here Flow of energy: Example Pyramid Example food chain MAY NOT USE this one